A method and device for monitoring a fault of a wind power generator set. The method includes the following steps: performing (101) fault identification on a component in a wind power generator set; and presenting (102) an identified fault using a three-dimensional model of the component. The device includes corresponding identifying module (61) and presenting module (62). By using the method and device, the fault monitor can intuitively observe the fault existed in the component, which not only is beneficial for taking effective fault processing measures before a minor fault evolves into a serious fault and thus reduces the harm of the fault, but also reduces the experience requirements for the fault monitor and avoids the process that the fault monitor in the prior art analyzes a two-dimensional curve to identify whether there is a fault in the component according to his experience.